precision planetary gearbox

Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to regulate a huge load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the motor torque, and so current, would have to be as many times increased as the lowering ratio which can be used. Moog offers a selection of precision planetary gearbox windings in each framework size that, combined with a selection of reduction ratios, offers an range of solution to productivity requirements. Each combination of engine and gearhead offers unique advantages.
Precision Planetary Gearheads
gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Accuracy Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high accuracy inline planetary servo travel will satisfy your most demanding automation applications. The compact style, universal housing with accuracy bearings and accuracy planetary gearing provides excessive torque density and will be offering high positioning efficiency. Series P offers exact ratios from 3:1 through 40:1 with the best efficiency and lowest backlash in the industry.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
Outcome 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
As a result of load sharing attributes of multiple tooth contacts,planetary gearboxes supply the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics in high speeds combined with the associated load sharing make planetary-type gearheads ideal for servo applications
Accurate helical technology provides elevated tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces even and quiet operation
One piece planet carrier and outcome shaft design reduces backlash
Single step machining process
Assures 100% concentricity Heightens 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, huge radial loads, low backlash, large input speeds and a tiny package size. Custom variations are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest overall performance to meet your applications torque, inertia, speed and reliability requirements. Helical gears present smooth and quiet operation and create higher electrical power density while keeping a tiny envelope size. Obtainable in multiple frame sizes and ratios to meet 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 ability, lower backlash, and noiseless operation
• Ring gear minimize into housing provides greater torsional stiffness
• Widely spaced angular speak to bearings provide productivity shaft with huge radial and axial load capability
• Plasma nitride heat treatment for gears for remarkable surface have on and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting packages for direct and convenient 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
Body 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
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY By NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of preference” for Servo Gearheads
Repeated misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads because of their inherent low backlash; low backlash is normally the main characteristic requirement for a servo gearboxes; backlash is a way of measuring the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems can be designed and built only as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement for servo-structured automation applications. A moderately low backlash is a good idea (in applications with very high start/stop, frontward/reverse cycles) in order to avoid interior shock loads in the apparatus mesh. That said, with today’s high-resolution motor-feedback devices and associated action controllers it is easy to compensate for backlash anytime there is a transform in the rotation or torque-load direction.
If, for the moment, we discount backlash, after that what are the factors for selecting a even more expensive, seemingly more technical planetary devices for servo gearheads? What advantages do planetary gears present?
High Torque Density: Small Design
An important requirement of automation applications is huge torque capacity in a compact and light bundle. This high torque density requirement (a high torque/quantity or torque/pounds ratio) is very important to automation applications with changing high 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 equipment with say three planets can transfer 3 x the torque of an identical sized fixed axis “typical” spur gear system
Rotational Stiffness/Elasticity
Large rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading conditions. The strain distribution unto multiple equipment mesh points signifies that the load is backed by N contacts (where N = number of planet gears) hence raising the torsional stiffness of the gearbox by factor N. This means it substantially lowers the lost action compared to a similar size standard gearbox; and this is what is desired.
Low Inertia
Added inertia results within an extra torque/energy requirement of both acceleration and deceleration. Small gears in planetary system cause lower inertia. Compared to a same torque rating standard gearbox, it is a reasonable approximation to say that the planetary gearbox inertia is usually smaller by the square of the amount of planets. Once again, this advantage is normally rooted in the distribution or “branching” of the load into multiple equipment mesh locations.
High Speeds
Modern day servomotors run at excessive rpm’s, hence a servo gearbox should be able to operate in a reliable manner at high source speeds. For servomotors, 3,000 rpm is pretty much the standard, and actually speeds are continuously increasing in order to optimize, increasingly intricate application requirements. Servomotors jogging at speeds in excess of 10,000 rpm aren’t unusual. From a score point of view, with increased swiftness the power density of the engine increases proportionally with no real size enhance of the electric motor or electronic drive. Thus, the amp rating stays about the same while simply the voltage must be increased. An important factor is with regards to the lubrication at excessive operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if operating at high speeds for the reason that lubricant is usually slung away. Only special means such as high-priced pressurized forced lubrication systems can solve this issue. Grease lubrication is normally impractical due to its “tunneling effect,” where the grease, as time passes, is pushed apart and cannot movement back to the mesh.
In planetary systems the lubricant cannot escape. It is continuously redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring safe lubrication practically in virtually any mounting position and at any acceleration. Furthermore, planetary gearboxes can be grease lubricated. This feature is normally inherent in planetary gearing due to the relative movement between the several gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For less complicated computation, it is recommended that the planetary gearbox ratio is an actual integer (3, 4, 6…). Since we are so used to the decimal system, we have a tendency to use 10:1 despite the fact that it has no practical advantage for the pc/servo/motion controller. Truly, as we will see, 10:1 or higher ratios will be the weakest, using minimal “balanced” size gears, and hence have the lowest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are participating in the same plane. Almost all the epicyclical gears found in servo applications will be of the simple planetary design. Physique 2a illustrates a cross-section of these kinds of a planetary gear set up with its central sun equipment, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox displayed in the number is obtained immediately from the initial kinematics of the system. It is obvious a 2:1 ratio is not possible in a simple planetary gear program, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would have to possess the same size as the ring gear. Figure 2b shows sunlight gear size for unique ratios. With increased ratio the sun gear diameter (size) is decreasing.
Since gear size affects loadability, the ratio is a strong and direct affect to the torque rating. Figure 3a reveals 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 earth bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is normally a well-balanced ratio, with sun and planets having the same size. 5:1 and 6:1 ratios still yield reasonably good balanced equipment sizes between planets and sunshine. With higher ratios approaching 10:1, the small sun gear becomes a solid limiting component for the transferable torque. Simple planetary designs with 10:1 ratios have very small sun gears, which sharply limits torque rating.
How Positioning Precision and Repeatability is Suffering from the Precision and Quality Class of the Servo Gearhead
As previously mentioned, this is a general misconception that the backlash of a gearbox is a way of measuring the product quality or precision. The fact is that the backlash features practically nothing to perform with the product quality or precision of a gear. Simply the regularity of the backlash can be viewed as, up to certain level, a form of measure of gear top quality. From the application perspective the relevant dilemma is, “What gear houses are influencing the precision of the motion?”
Positioning accuracy is a way of measuring how precise a desired position is reached. In a shut loop system the prime determining/influencing factors of the positioning accuracy are the accuracy and image resolution of the feedback unit and where the position is definitely measured. If the positioning is measured at the ultimate productivity of the actuator, the effect of the mechanical pieces can be practically eliminated. (Direct position measurement is used mainly in high precision applications such as machine equipment). In applications with a lower positioning accuracy necessity, the feedback transmission is produced by a responses devise (resolver, encoder) in the electric motor. In this case auxiliary mechanical components mounted on the motor like a gearbox, couplings, pulleys, belts, etc. will affect the positioning accuracy.
We manufacture and style high-quality gears together with complete speed-reduction systems. For build-to-print customized parts, assemblies, design, engineering and manufacturing providers speak to our engineering group.
Speed reducers and equipment trains can be categorized according to gear type and also 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
right angle and dual productivity right angle planetary gearheads
We realize you may not be interested in choosing the ready-to-use quickness reducer. For anybody who wish to design your personal special gear teach or velocity reducer we give you a broad range of accuracy gears, types, sizes and materials, available from stock.