Precision Planetary Gearheads
The primary reason to use a gearhead is that it creates it possible to regulate a large load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the electric motor torque, and thus current, would have to be as much times increased as the decrease ratio which is used. Moog offers an array of windings in each framework size that, combined with an array of reduction ratios, provides an range of solution to end result requirements. Each blend of motor and gearhead offers exceptional advantages.
Precision Planetary Gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo drive will satisfy your most demanding automation applications. The compact design, universal housing with accuracy bearings and accuracy planetary gearing provides substantial torque density while offering high positioning overall performance. Series P offers actual ratios from 3:1 through 40:1 with the best efficiency and lowest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
Productivity 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: Result with or without keyway
As a result of load sharing attributes of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for any given envelope
Balanced planetary kinematics at high speeds combined with associated load sharing generate planetary-type gearheads suitable for servo applications
Authentic helical technology provides elevated tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces smooth and quiet operation
One piece planet carrier and result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Increases torsional rigidity
Efficient lubrication forever
The great precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and offer high torque, high radial loads, low backlash, high input speeds and a little package size. Custom versions 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 provide smooth and quiet procedure and create higher ability density while maintaining a little envelope size. Obtainable in multiple frame sizes and ratios to meet up a variety of application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide even more torque capacity, lower backlash, and peaceful operation
• Ring gear trim into housing provides precision planetary gearbox greater torsional stiffness
• Widely spaced angular contact bearings provide end result shaft with high radial and axial load capability
• Plasma nitride heat therapy for gears for superb surface use and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting packages for direct and convenient assembly to hundreds of different motors
• Antenna pedestals
• Robotic actuation and propulsion
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 Rate (RPM)6000
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of Choice” for Servo Gearheads
Repeated misconceptions regarding planetary gears systems involve backlash: Planetary systems are being 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 way of measuring the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems can be designed and constructed simply as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement for servo-centered automation applications. A moderately low backlash is a good idea (in applications with very high start/stop, forward/reverse cycles) to avoid internal shock loads in the gear mesh. That said, with today’s high-quality motor-feedback devices and associated action controllers it is simple to compensate for backlash anytime there exists a change in the rotation or torque-load direction.
If, for as soon as, we discount backlash, then what are the reasons for selecting a 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 capacity in a concise and light bundle. This substantial torque density requirement (a higher torque/volume or torque/pounds ratio) is important for automation applications with changing large dynamic loads in order to avoid additional system inertia.
Depending upon the amount of planets, planetary systems distribute the transferred torque through multiple equipment mesh points. This implies a planetary equipment with declare three planets can transfer 3 x the torque of a similar sized fixed axis “regular” spur gear system
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 load distribution unto multiple gear mesh points ensures that the load is reinforced by N contacts (where N = quantity of planet gears) consequently increasing the torsional stiffness of the gearbox by element N. This means it significantly lowers the lost movement compared to an identical size standard gearbox; which is what’s desired.
Added inertia results in an additional torque/energy requirement for both acceleration and deceleration. Small gears in planetary system result in lower inertia. Compared to a same torque ranking standard gearbox, this is a reasonable approximation to state that the planetary gearbox inertia is definitely smaller by the square of the amount of planets. Once again, this advantage is definitely rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
Contemporary servomotors run at great rpm’s, hence a servo gearbox should be in a position to operate in a trusted manner at high insight speeds. For servomotors, 3,000 rpm is practically the standard, and actually speeds are constantly increasing to be able to optimize, increasingly intricate application requirements. Servomotors running at speeds more than 10,000 rpm are not unusual. From a ranking viewpoint, with increased acceleration the energy density of the engine increases proportionally without the real size enhance of the motor or electronic drive. Hence, the amp rating stays about the same while only the voltage must be increased. A key point is with regards to the lubrication at high operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if operating at high speeds since the lubricant is definitely slung away. Only specialized means such as costly pressurized forced lubrication devices can solve this problem. Grease lubrication is definitely impractical because of its “tunneling effect,” in which the grease, as time passes, is pushed apart and cannot move back to the mesh.
In planetary systems the lubricant cannot escape. It really is continually redistributed, “pushed and pulled” or “mixed” into the equipment contacts, ensuring safe lubrication practically in any mounting location and at any swiftness. Furthermore, planetary gearboxes could be grease lubricated. This characteristic is certainly inherent in planetary gearing because of the relative movement between the various gears making up the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For easier computation, it is desired that the planetary gearbox ratio can be an exact integer (3, 4, 6…). Since we are so used to the decimal program, we have a tendency to use 10:1 despite the fact that this has no practical gain for the computer/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 hence have the cheapest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are participating in the same plane. Almost all the epicyclical gears used in servo applications are of this simple planetary design. Body 2a illustrates a cross-section of this kind of a planetary gear arrangement with its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox displayed in the physique is obtained directly from the unique kinematics of the machine. It is obvious a 2:1 ratio is not possible in a simple planetary gear program, since to satisfy the previous equation for a ratio of 2:1, the sun gear would have to have the same size as the ring gear. Figure 2b shows the sun gear size for different ratios. With increased ratio sunlight gear size (size) is decreasing.
Since gear size influences 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 simple system. At 3:1 ratio, the sun gear is large and the planets will be small. The planets have become “skinny walled”, limiting the space for the planet bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is definitely a well-balanced ratio, with sun and planets having the same size. 5:1 and 6:1 ratios still yield pretty good balanced equipment sizes between planets and sun. With bigger ratios approaching 10:1, the tiny sun gear becomes a strong limiting component for the transferable torque. Simple planetary designs with 10:1 ratios have really small sun gears, which sharply limitations torque rating.
How Positioning Reliability and Repeatability is Affected by the Precision and Top quality Class of the Servo Gearhead
As previously mentioned, it is a general misconception that the backlash of a gearbox is a measure of the quality or precision. The truth is that the backlash offers practically nothing to perform with the product quality or precision of a gear. Simply the consistency of the backlash can be considered, up to certain degree, a form of measure of gear top quality. From the application point of view the relevant question is, “What gear real estate are influencing the accuracy of the motion?”
Positioning accuracy is a measure of how specific a desired job is reached. In a shut loop system the prime determining/influencing factors of the positioning accuracy are the accuracy and resolution of the feedback machine and where the position is usually measured. If the positioning is measured at the final result of the actuator, the influence of the mechanical parts can be practically eliminated. (Immediate position measurement is used mainly in high accuracy applications such as machine tools). In applications with a lesser positioning accuracy requirement, the feedback signal is produced by a opinions devise (resolver, encoder) in the motor. In this case auxiliary mechanical components attached to the motor such as a gearbox, couplings, pulleys, belts, etc. will effect the positioning accuracy.
We manufacture and style high-quality gears together with complete speed-reduction devices. For build-to-print customized parts, assemblies, design, engineering and manufacturing offerings contact our engineering group.
Speed reducers and equipment trains can be classified according to gear type as well as relative position of suggestions 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 outcome right angle planetary gearheads
We realize you might not exactly be interested in choosing the ready-to-use speed reducer. For those of you who wish to design your unique special gear coach or quickness reducer we provide a broad range of precision gears, types, sizes and materials, available from stock.
Precision Planetary Gearheads