Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to control a large load inertia with a comparatively small motor inertia. Without the 
gearhead, acceleration or velocity control of the load would require that the motor torque, and therefore current, would need to be as much times higher as the reduction ratio which is used. Moog offers an array of windings in each frame size that, combined with a selection of reduction ratios, provides an assortment of solution to result requirements. Each combination of precision planetary gearbox 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 Precision Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Accuracy 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 accuracy planetary gearing provides substantial torque density and will be offering high positioning overall performance. Series P offers actual ratios from 3:1 through 40:1 with the best 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.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Matches any servo motor
Output Options: Outcome 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 just about any given envelope
Balanced planetary kinematics in high speeds combined with associated load sharing generate 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 soft and quiet operation
One piece world carrier and outcome shaft design reduces backlash
Single step machining process
Assures 100% concentricity Increases torsional rigidity
Efficient lubrication for life
The substantial precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and offer high torque, large radial loads, low backlash, substantial input speeds and a little package size. Custom editions are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest effectiveness to meet your applications torque, inertia, speed and accuracy requirements. Helical gears present smooth and quiet operation and create higher electric power density while retaining a little envelope size. Obtainable in multiple body sizes and ratios to meet up 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 even more torque capability, lower backlash, and quiet operation
• Ring gear lower into housing provides increased torsional stiffness
• Widely spaced angular contact bearings provide outcome shaft with huge radial and axial load capability
• Plasma nitride heat therapy for gears for excellent 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
Applications
• Packaging
• Processing
• Bottling
• Milling
• Antenna pedestals
• Conveyors
• Robotic actuation and propulsion
PERFORMANCE CHARACTERISTICS
PERFORMANCEHigh Precision
CONFIGURATIONInline
GEAR GEOMETRYHelical Planetary
Body 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 preference” for Servo Gearheads
Consistent 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 normally a measure of the accuracy of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems can be designed and built merely as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement for servo-centered automation applications. A moderately low backlash is advisable (in applications with high start/stop, frontward/reverse cycles) in order to avoid inner shock loads in the apparatus mesh. That said, with today’s high-quality motor-feedback equipment and associated action controllers it is simple to compensate for backlash anytime there exists a adjust in the rotation or torque-load direction.
If, for as soon as, we discount backlash, in that case what are the factors for selecting a even more expensive, seemingly more technical planetary systems for servo gearheads? What advantages do planetary gears give?
High Torque Density: Small Design
An important requirement of automation applications is great torque ability in a concise and light package. This great torque density requirement (a higher torque/volume or torque/excess weight ratio) is very important to automation applications with changing high dynamic loads in order to avoid additional system inertia.
Depending upon the quantity of planets, planetary systems distribute the transferred torque through multiple equipment mesh points. This means a planetary equipment with declare three planets can transfer 3 x the torque of an identical sized fixed axis “common” 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 circumstances. The load distribution unto multiple gear mesh points means that the load is backed by N contacts (where N = amount of planet gears) consequently increasing the torsional stiffness of the gearbox by element N. This means it noticeably lowers the lost movement compared to a similar size standard gearbox; and this is what’s desired.
Low Inertia
Added inertia results in an added torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary system cause lower inertia. In comparison to a same torque score standard gearbox, it is a good approximation to state that the planetary gearbox inertia is certainly smaller by the square of the amount of planets. Once again, this advantage is normally 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 should be able to operate in a reliable manner at high input speeds. For servomotors, 3,000 rpm is almost the standard, and in fact speeds are constantly increasing so that you can optimize, increasingly complex application requirements. Servomotors operating at speeds in excess of 10,000 rpm are not unusual. From a score perspective, with increased speed the power density of the electric motor increases proportionally without the real size enhance of the electric motor or electronic drive. Hence, the amp rating remains about the same while only the voltage should be increased. A significant factor is in regards to the lubrication at high operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if running at high speeds since the lubricant can be slung away. Only exceptional means such as pricey pressurized forced lubrication devices can solve this problem. Grease lubrication can be impractical due to its “tunneling effect,” where the grease, as time passes, is pushed apart 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 equipment contacts, ensuring safe lubrication practically in any mounting placement and at any velocity. Furthermore, planetary gearboxes can be grease lubricated. This feature is inherent in planetary gearing as a result of the relative motion between the several gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For simpler computation, it is favored that the planetary gearbox ratio is an specific integer (3, 4, 6…). Since we are very much accustomed to the decimal program, we tend to use 10:1 even though this has no practical benefits for the computer/servo/motion controller. Actually, as we will see, 10:1 or more ratios are the weakest, using the least “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 used in servo applications happen to be of this simple planetary design. Body 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 proven in the physique is obtained immediately from the unique kinematics of the machine. It is obvious 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, sunlight gear would have to possess the same diameter as the ring gear. Figure 2b shows sunlight gear size for unique ratios. With increased ratio sunlight gear size (size) is decreasing.
Since gear size influences loadability, the ratio is a solid and direct impact to the torque ranking. Figure 3a displays the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, sunlight gear is large and the planets are small. The planets are becoming “skinny walled”, limiting the space for the planet bearings and carrier pins, therefore limiting the loadability. The 4:1 ratio can be a well-well balanced ratio, with sunlight and planets getting the same size. 5:1 and 6:1 ratios still yield pretty good balanced gear sizes between planets and sunshine. With larger ratios approaching 10:1, the small sun equipment becomes a strong limiting component for the transferable torque. Simple planetary patterns with 10:1 ratios have really small sunlight gears, which sharply limitations torque rating.
How Positioning Accuracy and Repeatability is Affected by the Precision and Top quality Category 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 has practically nothing to perform with the product quality or precision of a gear. Just the consistency of the backlash can be viewed as, up to certain level, a form of way of measuring gear top quality. From the application viewpoint the relevant dilemma is, “What gear homes are influencing the precision of the motion?”
Positioning precision is a way of measuring how actual a desired job is reached. In a closed loop system the primary determining/influencing factors of the positioning accuracy are the accuracy and quality of the feedback product and where the position is usually measured. If the position is certainly measured at the ultimate outcome of the actuator, the effect of the mechanical elements can be practically eliminated. (Immediate position measurement can be used mainly in high accuracy applications such as for example machine equipment). In applications with a lesser positioning accuracy need, the feedback transmission is made by a opinions devise (resolver, encoder) in the motor. In this case auxiliary mechanical components mounted on the motor like a gearbox, couplings, pulleys, belts, etc. will affect the positioning accuracy.
We manufacture and style high-quality gears in addition to complete speed-reduction devices. For build-to-print custom parts, assemblies, style, engineering and manufacturing products and services get in touch with our engineering group.
Speed reducers and gear trains can be categorized according to gear type along with 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 outcome right angle planetary gearheads
We realize you might not exactly be interested in choosing the ready-to-use acceleration reducer. For anybody who want to design your have special gear teach or quickness reducer we offer a broad range of precision gears, types, sizes and material, available from stock.