Precision Planetary Gearheads
The primary reason to use 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 motor torque, and so current, would have to be as many times greater as the lowering ratio which is used. Moog offers a selection of windings in each body size that, combined with a selection of reduction ratios, provides an range of precision planetary gearbox solution to outcome requirements. Each mixture of electric motor and gearhead offers one of a kind 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 Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will gratify your most demanding automation applications. The compact style, universal housing with precision bearings and precision planetary gearing provides excessive torque density and will be offering high positioning efficiency. Series P offers specific ratios from 3:1 through 40:1 with the highest efficiency and cheapest backlash in the market.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
Output Torque: Up to 1 1,500 Nm (13,275 lb.in.)
Gear Ratios: Up to 100:1 in two stages
Input Options: Matches any servo motor
Output Options: Productivity 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 associated load sharing produce planetary-type gearheads perfect for servo applications
True helical technology provides increased tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces easy and quiet operation
One piece planet carrier and productivity shaft design reduces backlash
Single step machining process
Assures 100% concentricity Heightens torsional rigidity
Efficient lubrication forever
The excessive precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and provide high torque, high radial loads, low backlash, large input speeds and a small package size. Custom versions are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest effectiveness to meet up your applications torque, inertia, speed and precision requirements. Helical gears provide smooth and quiet operation and create higher electricity density while maintaining a small envelope size. Available 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 more torque capacity, lower backlash, and silent operation
• Ring gear lower into housing provides better torsional stiffness
• 
Widely spaced angular contact bearings provide productivity shaft with large radial and axial load capability
• Plasma nitride heat therapy for gears for excellent surface have on and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting kits for direct and easy 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
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
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “Program of preference” for Servo Gearheads
Recurrent misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads due to their inherent low backlash; low backlash is certainly the main characteristic requirement of a servo gearboxes; backlash is certainly a measure of the precision of the planetary gearbox.
The truth is, fixed-axis, standard, “spur” gear arrangement systems could be designed and constructed merely as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-established automation applications. A moderately low backlash is recommended (in applications with high start/stop, forwards/reverse cycles) in order to avoid inner shock loads in the gear mesh. That said, with today’s high-resolution motor-feedback units and associated motion controllers it is easy to compensate for backlash anytime there exists a transform in the rotation or torque-load direction.
If, for as soon as, we discount backlash, after that what are the causes for selecting a more expensive, seemingly more complex planetary devices for servo gearheads? What advantages do planetary gears present?
High Torque Density: Small Design
An important requirement for automation applications is substantial torque capacity in a concise and light package. This excessive torque density requirement (a high torque/volume or torque/pounds 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 equipment mesh points. This means a planetary equipment with state three planets can transfer 3 x the torque of a similar sized fixed axis “normal” spur gear system
Rotational Stiffness/Elasticity
Substantial rotational (torsional) stiffness, or minimized elastic windup, is very important to applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading circumstances. The strain distribution unto multiple equipment mesh points means that the load is backed by N contacts (where N = amount of planet gears) consequently raising the torsional stiffness of the gearbox by factor N. This means it substantially lowers the lost action compared to an identical size standard gearbox; which is what’s desired.
Low Inertia
Added inertia results in an extra torque/energy requirement for both acceleration and deceleration. Small gears in planetary program bring about lower inertia. In comparison to a same torque ranking standard gearbox, it is a reasonable approximation to state that the planetary gearbox inertia is normally smaller by the square of the number of planets. Once again, this advantage can be rooted in the distribution or “branching” of the strain into multiple gear mesh locations.
High Speeds
Modern day servomotors run at substantial rpm’s, hence a servo gearbox must be able to operate in a trusted manner at high suggestions speeds. For servomotors, 3,000 rpm is almost the standard, and actually speeds are regularly increasing as a way to optimize, increasingly sophisticated application requirements. Servomotors working at speeds more than 10,000 rpm are not unusual. From a ranking viewpoint, with increased speed the power density of the electric motor increases proportionally without any real size maximize of the motor or electronic drive. Hence, the amp rating remains a comparable while just the voltage must be increased. A significant factor is with regards to the lubrication at large operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if running at high speeds because the lubricant is slung away. Only particular means such as pricey pressurized forced lubrication devices can solve this problem. Grease lubrication is impractical due to its “tunneling effect,” where the grease, over time, is pushed away and cannot circulation back to the mesh.
In planetary systems the lubricant cannot escape. It is constantly redistributed, “pushed and pulled” or “mixed” in to the gear contacts, ensuring secure lubrication practically in virtually any mounting job and at any quickness. Furthermore, planetary gearboxes could be grease lubricated. This characteristic can be inherent in planetary gearing as a result of the relative motion between different gears making up the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For a lot easier 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 tend to use 10:1 despite the fact that this has no practical advantage for the pc/servo/motion controller. Actually, as we will see, 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. Almost all the epicyclical gears found in servo applications happen to be of the simple planetary design. Shape 2a illustrates a cross-section of such 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 shown in the number is obtained immediately from the unique kinematics of the machine. It is obvious that a 2:1 ratio isn’t possible in a straightforward planetary gear system, since to satisfy the previous equation for a ratio of 2:1, the sun gear would have to possess the same size as the ring gear. Figure 2b shows sunlight gear size for numerous ratios. With increased ratio sunlight gear size (size) is decreasing.
Since gear size impacts loadability, the ratio is a strong and direct influence to the torque rating. Figure 3a shows the gears in a 3:1, 4:1, and 10:1 simple system. At 3:1 ratio, sunlight gear is significant and the planets happen to be small. The planets have become “skinny walled”, limiting the area for the planet bearings and carrier pins, hence 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 quite good balanced gear sizes between planets and sun. With higher ratios approaching 10:1, the tiny sun gear becomes a strong limiting aspect for the transferable torque. Simple planetary models with 10:1 ratios have very small sun gears, which sharply limits torque rating.
How Positioning Reliability and Repeatability is Affected by 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 quality or precision. The truth is that the backlash has practically nothing to perform with the quality or precision of a gear. Only the consistency of the backlash can be considered, up to certain level, a form of measure of gear top quality. From the application perspective the relevant problem is, “What gear real estate are influencing the precision of the motion?”
Positioning precision is a way of measuring how specific a desired posture is reached. In a closed loop system the prime determining/influencing elements of the positioning reliability are the accuracy and image resolution of the feedback product and where the job is certainly measured. If the position can be measured at the ultimate end result of the actuator, the effect of the mechanical components can be practically eliminated. (Direct position measurement is employed mainly in very high precision applications such as machine equipment). In applications with a lesser positioning accuracy necessity, the feedback transmission is generated by a feedback devise (resolver, encoder) in the electric motor. In this instance auxiliary mechanical components attached to the motor for instance a gearbox, couplings, pulleys, belts, etc. will impact the positioning accuracy.
We manufacture and design high-quality gears and complete speed-reduction devices. For build-to-print custom parts, assemblies, style, engineering and manufacturing services contact our engineering group.
Speed reducers and equipment trains can be categorized according to gear type in addition to relative position of source and end result shafts. SDP/SI offers a multitude of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
correct angle and dual productivity right angle planetary gearheads
We realize you might not be interested in choosing the ready-to-use rate reducer. For anybody who wish to design your have special gear educate or swiftness reducer we give a broad range of accuracy gears, types, sizes and material, available from stock.
