Precision Planetary Gearheads
The primary reason to employ 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 load would require that the electric motor torque, and precision planetary gearbox therefore current, would need to be as many times better as the lowering ratio which can be used. Moog offers a selection of windings in each body size that, combined with an array of reduction ratios, offers an assortment of solution to output requirements. Each mixture of engine and gearhead offers completely unique advantages.
Precision Planetary Gearheads
gearheads
32 mm Low Cost Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Accuracy 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 huge torque density while offering high positioning performance. Series P offers exact 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
Productivity Torque: Up to 1 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Matches any servo motor
Output Options: Productivity with or without keyway
Product Features
Due to the load sharing attributes of multiple tooth contacts,planetary gearboxes supply the highest torque and stiffness for any given envelope
Balanced planetary kinematics for high speeds combined with associated load sharing help to make planetary-type gearheads suitable for servo applications
The case helical technology provides improved tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces even and quiet operation
One piece planet carrier and output shaft design reduces backlash
Single step machining process
Assures 100% concentricity Heightens torsional rigidity
Efficient lubrication for life
The excessive precision PS-series inline 
helical planetary gearheads can be found in 60-220mm frame sizes and offer high torque, large radial loads, low backlash, excessive input speeds and a small package size. Custom types are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest efficiency to meet up your applications torque, inertia, speed and precision requirements. Helical gears present smooth and quiet operation and create higher vitality density while keeping a small envelope size. Available in multiple frame sizes and ratios to meet many different 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 tranquil operation
• Ring gear slice into housing provides higher torsional stiffness
• Widely spaced angular get in touch with bearings provide end result shaft with high radial and axial load capability
• Plasma nitride heat therapy for gears for exceptional surface have on and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting kits 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
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 Velocity (RPM)6000
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY AT NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System 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 definitely the main characteristic requirement of a servo gearboxes; backlash is normally a measure of the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and developed just as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-centered automation applications. A moderately low backlash is advisable (in applications with very high start/stop, ahead/reverse cycles) to avoid internal shock loads in the apparatus mesh. That said, with today’s high-resolution motor-feedback units and associated action controllers it is easy to compensate for backlash anytime there exists a switch in the rotation or torque-load direction.
If, for the moment, we discount backlash, in that case what are the factors for selecting a even more expensive, seemingly more complex planetary systems for servo gearheads? What advantages do planetary gears offer?
High Torque Density: Compact Design
An important requirement for automation applications is large torque capacity in a compact and light bundle. This great torque density requirement (a higher torque/quantity or torque/weight ratio) is important for automation applications with changing great dynamic loads to avoid additional system inertia.
Depending upon the quantity of planets, planetary systems distribute the transferred torque through multiple equipment mesh points. This implies a planetary equipment with state three planets can transfer 3 x the torque of an identical sized fixed axis “standard” spur gear system
Rotational Stiffness/Elasticity
Huge rotational (torsional) stiffness, or minimized elastic windup, is very important to applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading conditions. The load distribution unto multiple equipment mesh points means that the load is supported by N contacts (where N = number of planet gears) consequently increasing the torsional stiffness of the gearbox by factor N. This means it substantially lowers the lost movement compared to a similar size standard gearbox; which is what is desired.
Low Inertia
Added inertia results within an further torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary program bring about lower inertia. Compared to a same torque ranking standard gearbox, this is a reasonable approximation to say that the planetary gearbox inertia is usually smaller by the sq . of the amount of planets. Once again, this advantage is usually rooted in the distribution or “branching” of the load into multiple gear mesh locations.
High Speeds
Contemporary servomotors run at high rpm’s, hence a servo gearbox must be in a position to operate in a trusted manner at high suggestions speeds. For servomotors, 3,000 rpm is virtually the standard, and actually speeds are regularly increasing in order to optimize, increasingly complicated application requirements. Servomotors jogging at speeds in excess of 10,000 rpm are not unusual. From a rating point of view, with increased acceleration the energy density of the motor increases proportionally without any real size boost of the motor or electronic drive. As a result, the amp rating stays a comparable 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 jogging at high speeds as the lubricant is certainly slung away. Only exceptional means such as costly pressurized forced lubrication devices can solve this problem. Grease lubrication is definitely impractical due to its “tunneling effect,” where the grease, as time passes, is pushed apart and cannot stream back into the mesh.
In planetary systems the lubricant cannot escape. It is constantly redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring secure lubrication practically in any mounting situation and at any swiftness. Furthermore, planetary gearboxes could be grease lubricated. This feature can be inherent in planetary gearing as a result of the relative movement between the various gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For less complicated computation, it is favored that the planetary gearbox ratio can be an precise integer (3, 4, 6…). Since we are very much accustomed 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. In fact, as we will have, 10:1 or higher ratios are the weakest, using the least “balanced” size gears, and therefore have the cheapest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are engaging in the same plane. The vast majority of the epicyclical gears used in servo applications happen to be 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 demonstrated in the body is obtained directly from the unique kinematics of the system. It is obvious that a 2:1 ratio isn’t possible in a straightforward planetary gear program, since to satisfy the previous equation for a ratio of 2:1, sunlight gear would have to possess the same diameter as the ring gear. Figure 2b shows sunlight gear size for distinct ratios. With an increase of ratio sunlight gear diameter (size) is decreasing.
Since gear size influences loadability, the ratio is a solid and direct impact to the torque score. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 simple system. At 3:1 ratio, the sun gear is significant and the planets are small. The planets have become “slim walled”, limiting the space for the planet bearings and carrier pins, therefore limiting the loadability. The 4:1 ratio is a well-well balanced ratio, with sun and planets getting the same size. 5:1 and 6:1 ratios still yield rather good balanced gear sizes between planets and sunshine. With higher ratios approaching 10:1, the tiny sun gear becomes a strong limiting aspect for the transferable torque. Simple planetary designs with 10:1 ratios have very small sunlight gears, which sharply limitations torque rating.
How Positioning Precision and Repeatability is Suffering from the Precision and 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 quality or precision. The truth is that the backlash provides practically nothing to perform with the quality or precision of a gear. Just the regularity of the backlash can be viewed as, up to certain degree, a form of measure of gear quality. From the application point of view the relevant query is, “What gear homes are influencing the precision of the motion?”
Positioning accuracy is a measure of how actual a desired job is reached. In a closed loop system the prime determining/influencing factors of the positioning reliability are the accuracy and resolution of the feedback unit and where the situation is usually measured. If the position is definitely measured at the final output of the actuator, the impact of the mechanical elements can be practically eliminated. (Direct position measurement is employed mainly in high precision applications such as for example machine equipment). In applications with a lesser positioning accuracy need, the feedback signal is made by a feedback devise (resolver, encoder) in the engine. In this case auxiliary mechanical components attached to the motor such as a gearbox, couplings, pulleys, belts, etc. will impact the positioning accuracy.
We manufacture and design high-quality gears and complete speed-reduction systems. For build-to-print customized parts, assemblies, style, engineering and manufacturing products and services speak to our engineering group.
Speed reducers and gear trains can be classified according to equipment type and relative position of source and 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 quickness reducer. For those of you who want to design your individual special gear teach or rate reducer we provide a broad range of accuracy gears, types, sizes and material, available from stock.
