Precision Planetary Gearheads
The primary reason to employ a gearhead is that it makes it possible to regulate 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 so current, would have to be as many times increased as the reduction ratio which can be used. Moog offers an array of windings in each frame size that, coupled with an array of reduction ratios, offers an range of solution to output requirements. Each combo of electric motor and gearhead offers one of a kind advantages.
Precision Planetary Gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Accuracy 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 travel will fulfill your most demanding automation applications. The compact design, universal housing with accuracy bearings and accuracy planetary gearing provides large torque density and will be offering high positioning overall performance. Series P offers specific ratios from 3:1 through 40:1 with the highest efficiency and cheapest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
End result 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: Outcome with or without keyway
Because of the load sharing attributes of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for any given envelope
Balanced planetary kinematics in high speeds combined with the associated load sharing generate planetary-type gearheads ideal for servo applications
True helical technology provides elevated tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces even and quiet operation
One piece planet carrier and result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Boosts torsional rigidity
Efficient lubrication for life
The great precision PS-series inline helical planetary gearheads are available in 60-220mm frame sizes and provide high torque, excessive radial loads, low backlash, large input speeds and a small package size. Custom editions are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest overall performance to meet up your applications torque, inertia, speed and precision requirements. Helical gears provide smooth and quiet operation and create higher vitality density while retaining a little envelope size. Obtainable in multiple body sizes and ratios to meet various application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide more torque capacity, lower backlash, and silent operation
• Ring gear lower into housing provides greater torsional stiffness
• Widely spaced angular get in touch with bearings provide result shaft with excessive radial and axial load capability
• Plasma nitride heat treatment for gears for remarkable surface use and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting products for direct and convenient assembly to a huge selection of precision planetary gearbox 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 Acceleration (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “Program of Choice” for Servo Gearheads
Regular misconceptions regarding planetary gears systems involve backlash: Planetary systems are being used for servo gearheads as a result of their inherent low backlash; low backlash is definitely the main characteristic requirement of a servo gearboxes; backlash is normally a measure of the accuracy of the planetary gearbox.
The truth is, fixed-axis, standard, “spur” gear arrangement systems can be designed and developed simply as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement for servo-centered automation applications. A moderately low backlash is recommended (in applications with high start/stop, ahead/reverse cycles) to avoid inner shock loads in the gear mesh. That said, with today’s high-resolution motor-feedback equipment and associated movement controllers it is simple to compensate for backlash anytime you will find a transform in the rotation or torque-load direction.
If, for the moment, we discount backlash, in that case what are the factors for selecting a more expensive, seemingly more technical planetary devices for servo gearheads? What advantages do planetary gears present?
High Torque Density: Compact Design
An important requirement for automation applications is great torque capacity in a compact and light bundle. This high torque density requirement (a higher torque/volume or torque/excess weight ratio) is very important to automation applications with changing substantial dynamic loads in order to avoid additional system inertia.
Depending upon the number of planets, planetary devices distribute the transferred torque through multiple equipment mesh points. This means a planetary equipment with declare three planets can transfer three times the torque of an identical sized fixed axis “regular” spur gear system
Excessive rotational (torsional) stiffness, or minimized elastic windup, is very important to applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading conditions. The load distribution unto multiple equipment mesh points implies that the load is reinforced by N contacts (where N = number of planet gears) consequently raising the torsional stiffness of the gearbox by element N. This means it considerably lowers the lost action compared to an identical size standard gearbox; which is what’s desired.
Added inertia results within an added torque/energy requirement for both acceleration and deceleration. Small gears in planetary system bring about lower inertia. Compared to a same torque ranking standard gearbox, this is a good approximation to state that the planetary gearbox inertia is smaller by the sq . of the number of planets. Once again, this advantage is normally rooted in the distribution or “branching” of the strain into multiple gear mesh locations.
Modern day servomotors run at great rpm’s, hence a servo gearbox should be able to operate in a trusted manner at high type speeds. For servomotors, 3,000 rpm is pretty much the standard, and in fact speeds are frequently increasing to be able to optimize, increasingly complicated application requirements. Servomotors jogging at speeds in excess of 10,000 rpm aren’t unusual. From a ranking perspective, with increased speed the energy density of the electric motor increases proportionally with no real size maximize of the electric motor or electronic drive. Therefore, the amp rating remains about the same while just the voltage must be increased. A key point is with regards to the lubrication at huge operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if operating at high speeds as the lubricant is certainly slung away. Only exceptional means such as expensive pressurized forced lubrication systems can solve this issue. Grease lubrication is usually impractical due to its “tunneling effect,” in which the grease, over time, is pushed apart and cannot flow back into the mesh.
In planetary systems the lubricant cannot escape. It is continuously redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring secure lubrication practically in any mounting posture and at any acceleration. Furthermore, planetary gearboxes could be grease lubricated. This feature is inherent in planetary gearing as a result of the relative movement between the several gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For a lot easier computation, it is favored that the planetary gearbox ratio can be an actual integer (3, 4, 6…). Since we are so used to the decimal system, we have a tendency to use 10:1 even though it has no practical benefits for the computer/servo/motion controller. Truly, as we will have, 10:1 or higher ratios will be the weakest, using the least “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. The vast majority of the epicyclical gears found in servo applications are of this simple planetary design. Shape 2a illustrates a cross-section of such a planetary gear set up with its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox displayed in the determine is obtained straight from the unique kinematics of the machine. It is obvious that a 2:1 ratio isn’t possible in a simple planetary gear program, since to satisfy the previous equation for a ratio of 2:1, sunlight gear would have to possess the same size as the ring gear. Figure 2b shows the sun gear size for distinct ratios. With increased ratio the sun gear size (size) is decreasing.
Since gear size affects loadability, the ratio is a strong and direct effect 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 huge and the planets are small. The planets have become “thin walled”, limiting the area for the earth bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is usually a well-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 sun. With larger ratios approaching 10:1, the tiny sun equipment becomes a strong limiting component for the transferable torque. Simple planetary patterns with 10:1 ratios have very small sunshine 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 product quality or precision. The fact is that the backlash features practically nothing to perform with the product quality or accuracy of a gear. Simply the regularity of the backlash can be considered, up to certain level, a form of way of measuring gear top quality. From the application viewpoint the relevant query is, “What gear properties are influencing the accuracy of the motion?”
Positioning reliability is a measure of how specific a desired job is reached. In a closed loop system the primary determining/influencing elements of the positioning precision are the accuracy and quality of the feedback system and where the placement is usually measured. If the position is certainly measured at the final result of the actuator, the effect of the mechanical parts can be practically eliminated. (Direct position measurement is employed mainly in very high accuracy applications such as for example machine equipment). In applications with a lower positioning accuracy need, the feedback transmission is produced by a opinions devise (resolver, encoder) in the electric motor. In this instance auxiliary mechanical components attached to the motor such as a gearbox, couplings, pulleys, belts, etc. will influence 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 products and services contact our engineering group.
Speed reducers and gear trains can be categorized according to gear type along with relative position of insight and outcome shafts. SDP/SI offers a multitude of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual outcome right angle planetary gearheads
We realize you might not exactly be interested in selecting a ready-to-use quickness reducer. For those of you who want to design your individual special gear coach or speed reducer we offer a broad range of accuracy gears, types, sizes and material, available from stock.
Precision Planetary Gearheads