Precision Planetary Gearheads
The primary reason to use a gearhead is that it creates it possible to control a big load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the engine torque, and thus current, would need to be as much times increased as the reduction ratio which can be used. Moog offers an array of windings in each body size that, combined with an array of reduction ratios, provides an range of solution to productivity requirements. Each combo of electric motor and gearhead offers exclusive advantages.
Precision Planetary Gearheads
gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will satisfy your most demanding automation applications. The compact design, universal housing with precision bearings and precision planetary gearing provides great torque density and will be offering high positioning performance. Series P offers precise ratios from 3:1 through 40:1 with the best efficiency and cheapest backlash in the market.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
Productivity Torque: Up to at least one 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Suits any servo motor
Output Options: Output with or without keyway
Product Features
As a result of load sharing features of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for any given envelope
Balanced planetary kinematics for high speeds combined with the associated load sharing help to make planetary-type gearheads well suited for servo applications
Authentic helical technology provides elevated tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces precision planetary gearbox smooth and quiet operation
One piece world carrier and end result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Enhances torsional rigidity
Efficient lubrication forever
The great precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and provide high torque, high radial loads, low backlash, substantial input speeds and a tiny package size. Custom editions are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest performance to meet your applications torque, inertia, speed and accuracy requirements. Helical gears provide smooth and quiet operation and create higher power density while retaining a small envelope size. Obtainable in multiple body sizes and ratios to meet up a variety 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 more torque capability, lower backlash, and quiet operation
• Ring gear lower into housing provides increased torsional stiffness
• Widely spaced angular speak to bearings provide end result shaft with high radial and axial load capability
• Plasma nitride heat treatment for gears for good surface wear and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting packages for direct and convenient assembly to hundreds of different motors
Applications
• Packaging
• Processing
• Bottling
• Milling
• Antenna pedestals
• Conveyors
• Robotic actuation and propulsion
PERFORMANCE 
CHARACTERISTICS
PERFORMANCEHigh Precision
CONFIGURATIONInline
GEAR GEOMETRYHelical Planetary
FRAME 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 SPEED (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY In NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “Program of preference” for Servo Gearheads
Regular misconceptions regarding planetary gears systems involve backlash: Planetary systems are being used for servo gearheads because of their inherent low backlash; low backlash is normally the main characteristic requirement for a servo gearboxes; backlash can be a measure of the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and developed only as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement of servo-primarily based automation applications. A moderately low backlash is a good idea (in applications with high start/stop, forward/reverse cycles) 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 exists a adjust in the rotation or torque-load direction.
If, for as soon as, we discount backlash, then what are the causes for selecting a more expensive, seemingly more technical planetary devices for servo gearheads? What positive aspects do planetary gears give?
High Torque Density: Compact Design
An important requirement for automation applications is substantial torque capacity in a compact and light package. This substantial torque density requirement (a higher torque/quantity or torque/excess weight ratio) is very important to automation applications with changing large dynamic loads in order to avoid additional system inertia.
Depending upon the quantity of planets, planetary systems distribute the transferred torque through multiple gear mesh points. This implies a planetary gear with claim three planets can transfer 3 x the torque of an identical sized fixed axis “regular” spur gear system
Rotational Stiffness/Elasticity
Excessive rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading circumstances. The strain distribution unto multiple gear mesh points ensures that the load is reinforced by N contacts (where N = quantity of planet gears) hence increasing the torsional stiffness of the gearbox by point N. This means it significantly lowers the lost movement compared to an identical size standard gearbox; which is what’s desired.
Low Inertia
Added inertia results within an more torque/energy requirement of both acceleration and deceleration. Small gears in planetary system lead to lower inertia. In comparison to a same torque score standard gearbox, this is a fair approximation to state that the planetary gearbox inertia is definitely smaller by the square of the number of planets. Once again, this advantage is certainly rooted in the distribution or “branching” of the load into multiple gear mesh locations.
High Speeds
Modern servomotors run at great rpm’s, hence a servo gearbox should be in a position to operate in a trusted manner at high type speeds. For servomotors, 3,000 rpm is virtually the standard, and actually speeds are regularly increasing in order to optimize, increasingly intricate application requirements. Servomotors working at speeds more than 10,000 rpm aren’t unusual. From a score perspective, with increased quickness the energy density of the motor increases proportionally without any real size maximize of the engine or electronic drive. As a result, the amp rating remains a comparable while simply the voltage must be increased. A significant factor is with regards to the lubrication at substantial operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if jogging at high speeds because the lubricant is definitely slung away. Only specialized means such as costly pressurized forced lubrication devices can solve this problem. Grease lubrication is certainly impractical as a result of its “tunneling effect,” where the grease, as time passes, is pushed aside and cannot move back to the mesh.
In planetary systems the lubricant cannot escape. It is consistently redistributed, “pushed and pulled” or “mixed” into the gear contacts, ensuring safe lubrication practically in any mounting posture and at any swiftness. Furthermore, planetary gearboxes can be grease lubricated. This feature is definitely inherent in planetary gearing as a result of the relative movement between the different gears making up the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For less difficult computation, it is desired that the planetary gearbox ratio is an exact integer (3, 4, 6…). Since we are very much accustomed to the decimal program, we have a tendency to use 10:1 even though it has no practical benefits for the pc/servo/motion controller. In fact, as we will have, 10:1 or more ratios will be the weakest, using minimal “well-balanced” size gears, and therefore have the lowest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are participating in the same plane. The vast majority of the epicyclical gears used in servo applications are of the simple planetary design. Determine 2a illustrates a cross-section of such a planetary gear set up with its central sun gear, multiple planets (3), and the ring gear. The definition of the ratio of a planetary gearbox shown in the shape is obtained straight from the unique kinematics of the system. It is obvious a 2:1 ratio isn’t possible in a straightforward planetary gear program, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would need to have the same size as the ring equipment. Figure 2b shows the sun gear size for different ratios. With an increase of ratio the sun gear diameter (size) is decreasing.
Since gear size impacts loadability, the ratio is a solid and direct affect to the torque score. Figure 3a shows the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, sunlight gear is significant and the planets happen to be small. The planets have become “slim walled”, limiting the area for the planet bearings and carrier pins, therefore limiting the loadability. The 4:1 ratio is certainly a well-well-balanced ratio, with sunlight and planets having the same size. 5:1 and 6:1 ratios still yield pretty good balanced gear sizes between planets and sun. With larger ratios approaching 10:1, the small sun equipment becomes a strong limiting component for the transferable torque. Simple planetary patterns with 10:1 ratios have really small sun gears, which sharply limits torque rating.
How Positioning Accuracy and Repeatability is Affected by the Precision and Top quality Category of the Servo Gearhead
As previously mentioned, this is a general misconception that the backlash of a gearbox is a measure of the quality or precision. The fact is that the backlash provides practically nothing to do with the quality or precision of a gear. Just the consistency of the backlash can be considered, up to certain degree, a form of way of measuring gear quality. From the application viewpoint the relevant concern is, “What gear houses are influencing the accuracy of the motion?”
Positioning accuracy is a way of measuring how exact a desired situation is reached. In a closed loop system the prime determining/influencing factors of the positioning precision are the accuracy and image resolution of the feedback gadget and where the posture can be measured. If the positioning is certainly measured at the final end result 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 equipment). In applications with less positioning accuracy requirement, the feedback transmission is produced by a opinions devise (resolver, encoder) in the engine. In this instance auxiliary mechanical components mounted on the motor such as a gearbox, couplings, pulleys, belts, etc. will influence the positioning accuracy.
We manufacture and design high-quality gears together with complete speed-reduction systems. For build-to-print custom parts, assemblies, design, engineering and manufacturing companies get in touch with our engineering group.
Speed reducers and gear trains can be categorized according to gear type as well as relative position of type and end result shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
proper angle and dual end result right angle planetary gearheads
We realize you may well not be interested in choosing the ready-to-use swiftness reducer. For those of you who want to design your own special gear train or acceleration reducer we give a broad range of precision gears, types, sizes and materials, available from stock.
