Precision Planetary Gearheads
The primary reason to use a gearhead is that it makes it possible to control a sizable 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 therefore current, would have to be as much times greater as the decrease ratio which can be used. Moog offers a selection of windings in each frame size that, combined with an array of reduction ratios, provides an range of solution to outcome requirements. Each blend of engine 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 Precision Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high accuracy inline planetary servo travel will gratify your most demanding automation applications. The compact style, universal housing with precision bearings and accuracy planetary gearing provides great torque density and will be offering high positioning effectiveness. Series P offers specific ratios from 3:1 through 40:1 with the best efficiency and cheapest 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.)
Gear Ratios: Up to 100:1 in two stages
Input Options: Fits any servo motor
Output Options: Outcome with or without keyway
Product Features
Due to the load sharing characteristics of multiple tooth contacts,planetary gearboxes supply 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 suitable for servo applications
Authentic helical technology provides improved tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces even 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 for life
The large precision PS-series inline helical planetary gearheads are available in 60-220mm frame sizes and offer high torque, substantial radial loads, low backlash, great input speeds and a small package size. Custom variations are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest efficiency to meet your applications torque, inertia, speed and accuracy requirements. Helical gears offer smooth and quiet procedure and create higher power density while keeping a little envelope size. Available in multiple body sizes and ratios to meet up a range 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 noiseless operation
• Ring gear minimize into housing provides better torsional stiffness
• Widely spaced angular contact bearings provide end result shaft with excessive radial and axial load capability
• Plasma nitride heat therapy for gears for wonderful surface dress in and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting kits for direct and convenient assembly to hundreds of different motors
Applications
• Packaging
• Processing
• Bottling
• Milling
• Antenna pedestals
• precision planetary gearbox 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 Swiftness (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 preference” for Servo Gearheads
Frequent misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads as a result of their inherent low backlash; low backlash is the main characteristic requirement of a servo gearboxes; backlash is definitely a measure of the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and created only as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-centered automation applications. A moderately low backlash is highly recommended (in applications with high start/stop, onward/reverse cycles) to avoid internal shock loads in the apparatus mesh. That said, with today’s high-quality motor-feedback products and associated motion controllers it is easy to compensate for backlash anytime you will find a change 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 systems for servo gearheads? What advantages do planetary gears offer?
High Torque Density: Compact Design
An important requirement of automation applications is great torque ability in a compact and light package. This large torque density requirement (a high torque/volume or torque/fat ratio) is very important to automation applications with changing high dynamic loads to avoid additional system inertia.
Depending upon the quantity of planets, planetary devices distribute the transferred torque through multiple gear mesh points. This means a planetary gear with say three planets can transfer 3 x the torque of an identical sized fixed axis “normal” spur gear system
Rotational Stiffness/Elasticity
Substantial rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading circumstances. The load distribution unto multiple gear mesh points implies that the load is backed by N contacts (where N = number of planet gears) hence raising the torsional stiffness of the gearbox by issue N. This means it significantly lowers the lost action compared to a similar size standard gearbox; which is what is desired.
Low Inertia
Added inertia results within an additional torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary system result in lower inertia. In comparison to a same torque rating standard gearbox, this is a fair approximation to state that the planetary gearbox inertia can be smaller by the sq . of the amount of planets. Again, this advantage is definitely rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
High Speeds
Modern day servomotors run at large rpm’s, hence a servo gearbox must be in a position to operate in a trusted manner at high insight speeds. For servomotors, 3,000 rpm is virtually the standard, and actually speeds are frequently increasing as a way to optimize, increasingly complicated application requirements. Servomotors operating at speeds in excess of 10,000 rpm are not unusual. From a ranking point of view, with increased velocity the power density of the electric motor increases proportionally without any real size increase of the engine or electronic drive. Therefore, the amp rating stays about the same 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 working at high speeds since the lubricant is usually slung away. Only exceptional means such as pricey pressurized forced lubrication systems can solve this problem. Grease lubrication is impractical because of its “tunneling effect,” where the grease, as time passes, is pushed away and cannot stream back to the mesh.
In planetary systems the lubricant cannot escape. It really is continuously redistributed, “pushed and pulled” or “mixed” into the equipment contacts, ensuring safe lubrication practically in any mounting placement and at any acceleration. Furthermore, planetary gearboxes could be grease lubricated. This characteristic can be inherent in planetary gearing as a result of the relative action between different gears making up the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Perspective
For a lot easier computation, it is recommended that the planetary gearbox ratio is an specific integer (3, 4, 6…). Since we are so used to the decimal program, we tend to use 10:1 despite the fact that it has no practical advantage for the computer/servo/motion controller. Actually, as we will have, 10:1 or more ratios will be 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 are of the simple planetary design. Number 2a illustrates a cross-section of these kinds of a planetary gear set up using its central sun equipment, multiple planets (3), and the ring gear. The definition of the ratio of a planetary gearbox displayed in the shape is obtained straight from the initial kinematics of the machine. It is obvious a 2:1 ratio isn’t possible in a simple planetary gear program, since to satisfy the prior equation for a ratio of 2:1, the sun gear would need to possess the same diameter as the ring gear. Figure 2b shows sunlight gear size for diverse ratios. With an increase of ratio the sun gear diameter (size) is decreasing.
Since gear size influences loadability, the ratio is a solid and direct effect to the torque ranking. Figure 3a reveals 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 are small. The planets are becoming “thin walled”, limiting the space for the planet bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is usually a well-balanced ratio, with sunlight and planets getting the same size. 5:1 and 6:1 ratios still yield reasonably good balanced gear sizes between planets and sunlight. With bigger ratios approaching 10:1, the small sun gear becomes a strong limiting factor for the transferable torque. Simple planetary patterns with 10:1 ratios have really small sunshine gears, which sharply restrictions torque rating.
How Positioning Accuracy and Repeatability is Suffering from the Precision and Top quality School 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 possesses practically nothing to carry out with the product quality or precision of a gear. Just the consistency of the backlash can be considered, up to certain level, a form of way of measuring gear quality. From the application viewpoint the relevant dilemma is, “What gear properties are influencing the precision of the motion?”
Positioning reliability is a measure of how actual a desired location is reached. In a closed loop system the prime determining/influencing factors of the positioning reliability will be the accuracy and image resolution of the feedback product and where the posture is usually measured. If the positioning is normally measured at the ultimate result of the actuator, the influence of the mechanical elements can be practically eliminated. (Direct position measurement is utilized mainly in very high precision applications such as for example machine tools). In applications with a lesser positioning accuracy requirement, the feedback signal is made by a responses devise (resolver, encoder) in the engine. In this instance 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 along with complete speed-reduction systems. For build-to-print custom parts, assemblies, design, engineering and manufacturing solutions get in touch with our engineering group.
Speed reducers and equipment trains can be categorized according to gear type in addition to relative position of source and productivity shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual result 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 own special gear train or acceleration reducer we offer a broad range of precision gears, types, sizes and material, available from stock.