Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to regulate a sizable load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the electric motor torque, and so current, would need to be as many times higher as the lowering ratio which can be used. Moog offers an array of windings in each frame size that, coupled with a selection of reduction ratios, offers an assortment of solution to outcome requirements. Each combo of motor and gearhead offers exclusive advantages.
Precision Planetary Gearheads
gearheads
32 mm Low Cost Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Accuracy Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will meet your most demanding automation applications. The compact design, universal housing with accuracy bearings and accuracy planetary gearing provides great torque density and will be offering high positioning functionality. Series P offers specific ratios from 3:1 through 40:1 with the highest efficiency and cheapest backlash in the industry.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
Output Torque: Up to at least one 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Meets any servo motor
Output Options: 
Outcome with or without keyway
Product Features
Because of the load sharing features of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics for high speeds combined with the associated load sharing help to make planetary-type gearheads suitable for servo applications
True helical technology provides improved tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces easy and quiet operation
One piece world carrier and result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Enhances torsional rigidity
Efficient lubrication forever
The great precision precision planetary gearbox PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and provide high torque, huge radial loads, low backlash, huge input speeds and a small package size. Custom variants are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest overall performance to meet your applications torque, inertia, speed and precision requirements. Helical gears present smooth and quiet procedure and create higher electrical power density while maintaining a little envelope size. Obtainable in multiple framework sizes and ratios to meet a number of application requirements.
Markets
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
• Robotics
• Military
Features and Benefits
• Helical gears provide even more torque capability, lower backlash, and peaceful operation
• Ring gear lower into housing provides higher torsional stiffness
• Widely spaced angular contact bearings provide productivity shaft with huge radial and axial load capability
• Plasma nitride heat therapy for gears for excellent surface don and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting products for direct and easy assembly to a huge selection of different motors
Applications
• Packaging
• Processing
• Bottling
• Milling
• Antenna pedestals
• Conveyors
• Robotic actuation and propulsion
PERFORMANCE CHARACTERISTICS
PERFORMANCEHigh Precision
CONFIGURATIONInline
GEAR GEOMETRYHelical Planetary
Framework SIZE60mm | 90mm | 115mm | 142mm | 180mm | 220mm
STANDARD BACKLASH (ARC-MIN)< 4 to < 8
LOW BACKLASH (ARC-MIN)< 3 to < 6
NOMINAL TORQUE (NM)27 –
1808
NOMINAL TORQUE (IN-LBS)240 – 16091
RADIAL LOAD (N)1650 – 38000
RADIAL LOAD (LBS)370 – 8636
RATIO3, 4, 5, 7, 10, 15, 20, 25, 30, 40, 50, 70, 100:1
MAXIMUM INPUT Quickness (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY AT NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “Program of Choice” for Servo Gearheads
Consistent misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads because of their inherent low backlash; low backlash is the main characteristic requirement of a servo gearboxes; backlash is usually a measure of the accuracy of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems can be designed and built just as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-based automation applications. A moderately low backlash is recommended (in applications with high start/stop, onward/reverse cycles) in order to avoid interior shock loads in the apparatus mesh. Having said that, with today’s high-resolution motor-feedback devices and associated action controllers it is simple to compensate for backlash anytime there is a modify in the rotation or torque-load direction.
If, for as soon as, we discount backlash, then what are the factors for selecting a even more expensive, seemingly more technical planetary devices for servo gearheads? What positive aspects do planetary gears offer?
High Torque Density: Small Design
An important requirement of automation applications is great torque capacity in a concise and light package. This great torque density requirement (a high torque/volume or torque/fat ratio) is very important to automation applications with changing substantial dynamic loads in order to avoid additional system inertia.
Depending upon the number of planets, planetary systems distribute the transferred torque through multiple gear mesh points. This means a planetary gear with declare three planets can transfer three times the torque of an identical sized fixed axis “typical” spur gear system
Rotational Stiffness/Elasticity
Huge rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading conditions. The load distribution unto multiple equipment mesh points signifies that the load is reinforced by N contacts (where N = quantity of planet gears) hence increasing the torsional stiffness of the gearbox by component N. This means it considerably lowers the lost movement compared to an identical size standard gearbox; and this is what is desired.
Low Inertia
Added inertia results in an more torque/energy requirement for both acceleration and deceleration. Small gears in planetary program lead to lower inertia. In comparison to a same torque rating standard gearbox, it is a fair approximation to state that the planetary gearbox inertia is smaller by the square of the number of planets. Once again, this advantage is definitely rooted in the distribution or “branching” of the strain into multiple gear mesh locations.
High Speeds
Modern day servomotors run at excessive rpm’s, hence a servo gearbox should be in a position to operate in a reliable manner at high suggestions speeds. For servomotors, 3,000 rpm is almost the standard, and actually speeds are frequently increasing to be able to optimize, increasingly complex application requirements. Servomotors working at speeds more than 10,000 rpm are not unusual. From a score viewpoint, with increased speed the energy density of the engine increases proportionally with no real size enhance of the engine or electronic drive. Hence, the amp rating stays about the same while just the voltage should be increased. An important factor is in regards to the lubrication at excessive operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if working at high speeds since the lubricant is normally slung away. Only unique means such as expensive pressurized forced lubrication devices can solve this problem. Grease lubrication is definitely impractical as a result of its “tunneling effect,” in which the grease, as time passes, is pushed apart and cannot stream back into the mesh.
In planetary systems the lubricant cannot escape. It really is continuously redistributed, “pushed and pulled” or “mixed” into the equipment contacts, ensuring secure lubrication practically in any mounting situation and at any quickness. Furthermore, planetary gearboxes could be grease lubricated. This feature is definitely inherent in planetary gearing as a result of the relative movement between the several gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Perspective
For a lot easier computation, it is desired that the planetary gearbox ratio can be an actual integer (3, 4, 6…). Since we are very much accustomed to the decimal system, we tend to use 10:1 despite the fact that it has no practical gain for the computer/servo/motion controller. Truly, as we will see, 10:1 or higher ratios are the weakest, using minimal “well-balanced” size gears, and hence have the lowest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are engaging in the same plane. Almost all the epicyclical gears found in servo applications will be of the simple planetary design. Shape 2a illustrates a cross-section of this kind of a planetary gear set up using its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox proven in the shape is obtained straight from the initial kinematics of the machine. It is obvious that a 2:1 ratio isn’t possible in a simple planetary gear system, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would have to possess the same size as the ring equipment. Figure 2b shows the sun gear size for unique ratios. With an increase of ratio the sun gear diameter (size) is decreasing.
Since gear size influences loadability, the ratio is a strong and direct impact to the torque score. Figure 3a shows the gears in a 3:1, 4:1, and 10:1 straightforward system. At 3:1 ratio, the sun gear is significant and the planets happen to be small. The planets have become “skinny walled”, limiting the area for the earth bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is usually a well-well-balanced ratio, with sun and planets having the same size. 5:1 and 6:1 ratios still yield pretty good balanced gear sizes between planets and sunshine. With bigger ratios approaching 10:1, the small sun gear becomes a strong limiting point for the transferable torque. Simple planetary models with 10:1 ratios have very small sunlight gears, which sharply restrictions torque rating.
How Positioning Accuracy and Repeatability is Affected by the Precision and Top quality Course of the Servo Gearhead
As previously mentioned, it is a general misconception that the backlash of a gearbox is a way of measuring the product quality or precision. The truth is that the backlash has practically nothing to carry out with the product quality or accuracy of a gear. Only the regularity of the backlash can be viewed as, up to certain level, a form of way of measuring gear quality. From the application viewpoint the relevant query is, “What gear homes are influencing the precision of the motion?”
Positioning accuracy is a measure of how actual a desired placement is reached. In a closed loop system the primary determining/influencing factors of the positioning precision are the accuracy and resolution of the feedback product and where the situation is measured. If the position is certainly measured at the ultimate outcome of the actuator, the affect of the mechanical elements could be practically eliminated. (Direct position measurement is used mainly in high accuracy applications such as machine tools). In applications with a lesser positioning accuracy requirement, the feedback signal is produced by a opinions devise (resolver, encoder) in the electric motor. In cases like this auxiliary mechanical components attached to the motor like a gearbox, couplings, pulleys, belts, etc. will effect the positioning accuracy.
We manufacture and style high-quality gears together with complete speed-reduction devices. For build-to-print custom parts, assemblies, style, engineering and manufacturing services get in touch with our engineering group.
Speed reducers and equipment trains can be categorized according to gear type as well as relative position of insight and result shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
correct angle and dual output right angle planetary gearheads
We realize you might not exactly be interested in selecting a ready-to-use acceleration reducer. For anybody who want to design your personal special gear teach or velocity reducer we offer a broad range of accuracy gears, types, sizes and materials, available from stock.
