Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to control a big 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 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 framework size that, coupled with an array of reduction ratios, offers an range of solution to result requirements. Each combination 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 Accuracy Planetary Gearhead
120 mm Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high accuracy inline planetary servo drive will gratify your most demanding automation applications. The compact design, universal housing with accuracy bearings and precision planetary gearing provides high torque density while offering high positioning overall performance. Series P offers specific 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
Result Torque: Up to at least one 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Fits 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 in high speeds combined with associated load sharing make planetary-type gearheads ideal for servo applications
True helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces simple and quiet operation
One piece world carrier and end result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Enhances torsional rigidity
Efficient lubrication forever
The huge precision PS-series inline helical planetary gearheads are available in 60-220mm frame sizes and offer high torque, huge radial loads, low backlash, substantial input speeds and a tiny package size. Custom types are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest effectiveness to meet up your applications torque, inertia, speed and precision requirements. Helical gears present smooth and quiet operation and create higher electrical power density while maintaining a tiny envelope size. Available in multiple framework sizes and ratios to meet up a variety of application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
precision planetary gearbox Features and Benefits
• Helical gears provide more torque ability, lower backlash, and quiet operation
• Ring gear minimize into housing provides greater torsional stiffness
• Widely spaced angular get in touch with bearings provide productivity shaft with substantial radial and axial load capability
• Plasma nitride heat therapy for gears for excellent surface dress in and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting kits for direct and easy assembly to hundreds of different motors
• Antenna pedestals
• Robotic actuation and propulsion
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 Rate (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 Choice” for Servo Gearheads
Regular misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads due to their inherent low backlash; low backlash is the main characteristic requirement of a servo gearboxes; backlash is definitely a way of measuring the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and designed merely as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement for servo-based automation applications. A moderately low backlash is advisable (in applications with very high start/stop, onward/reverse cycles) to avoid internal shock loads in the gear mesh. That said, with today’s high-image resolution motor-feedback products and associated motion controllers it is easy to compensate for backlash anytime there is a alter in the rotation or torque-load direction.
If, for the moment, we discount backlash, after that what are the factors for selecting a more expensive, seemingly more complex planetary systems for servo gearheads? What advantages do planetary gears offer?
High Torque Density: Compact Design
An important requirement of automation applications is large torque capability in a concise and light bundle. This substantial torque density requirement (a higher torque/quantity or torque/excess weight ratio) is very important to automation applications with changing substantial dynamic loads to avoid additional system inertia.
Depending upon the number of planets, planetary systems distribute the transferred torque through multiple gear mesh points. This means a planetary gear with state three planets can transfer three times the torque of an identical sized fixed axis “common” 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 circumstances. The load distribution unto multiple gear mesh points ensures that the load is reinforced by N contacts (where N = amount of planet gears) therefore raising the torsional stiffness of the gearbox by component N. This implies it substantially lowers the lost movement compared to an identical size standard gearbox; and this is what's desired.
Added inertia results within an added torque/energy requirement for both acceleration and deceleration. The smaller gears in planetary program result in lower inertia. Compared to a same torque rating standard gearbox, this is a fair approximation to say that the planetary gearbox inertia is definitely smaller by the square of the number of planets. Again, this advantage is certainly rooted in the distribution or “branching” of the load into multiple equipment mesh locations.
Contemporary servomotors run at excessive rpm’s, hence a servo gearbox must be in a position to operate in a trusted manner at high insight speeds. For servomotors, 3,000 rpm is pretty much the standard, and actually speeds are regularly increasing so as to optimize, increasingly complicated application requirements. Servomotors jogging at speeds more than 10,000 rpm aren't unusual. From a rating perspective, with increased speed the power density of the motor increases proportionally without any real size enhance of the engine or electronic drive. Therefore, the amp rating stays a comparable while just 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 running at high speeds since the lubricant can be slung away. Only specialized means such as expensive pressurized forced lubrication systems can solve this problem. Grease lubrication is usually impractical as a result of its “tunneling effect,” in which the grease, as time passes, is pushed apart and cannot circulation back into the mesh.
In planetary systems the lubricant cannot escape. It really is continually redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring secure lubrication practically in virtually any mounting situation and at any rate. Furthermore, planetary gearboxes could be grease lubricated. This feature is definitely inherent in planetary gearing due to the relative action between the several gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For less difficult computation, it is favored that the planetary gearbox ratio can be an specific 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. Essentially, as we will have, 10:1 or higher ratios will be 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. The vast majority of the epicyclical gears found in servo applications are of the simple planetary design. Shape 2a illustrates a cross-section of these kinds of a planetary gear arrangement using its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox demonstrated in the figure 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 system, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would need to have the same size as the ring gear. Figure 2b shows the sun gear size for distinct ratios. With increased ratio sunlight gear diameter (size) is decreasing.
Since gear size affects loadability, the ratio is a strong and direct influence to the torque ranking. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 straightforward system. At 3:1 ratio, the sun gear is significant and the planets happen to be small. The planets have become “thin walled”, limiting the space for the earth bearings and carrier pins, therefore limiting the loadability. The 4:1 ratio is certainly 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 small sun gear becomes a solid limiting factor for the transferable torque. Simple planetary models with 10:1 ratios have really small sun gears, which sharply limits torque rating.
How Positioning Precision and Repeatability is Affected by the Precision and Quality Class of the Servo Gearhead
As previously mentioned, this 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 carry out with the quality or precision of a gear. Just the consistency of the backlash can be considered, up to certain degree, a form of measure of gear top quality. From the application viewpoint the relevant query is, “What gear houses are influencing the precision of the motion?”
Positioning precision is a measure of how actual a desired location is reached. In a shut loop system the prime determining/influencing factors of the positioning precision will be the accuracy and quality of the feedback gadget and where the position is measured. If the position is usually measured at the ultimate output of the actuator, the influence of the mechanical parts can be practically eliminated. (Immediate position measurement is utilized mainly in very high precision applications such as machine tools). In applications with a lower positioning accuracy necessity, the feedback transmission is generated 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 effect the positioning accuracy.
We manufacture and design high-quality gears and also complete speed-reduction devices. For build-to-print customized parts, assemblies, design, engineering and manufacturing companies speak to our engineering group.
Speed reducers and gear trains can be categorized according to gear type together with relative position of input and end result shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual output right angle planetary gearheads
We realize you might not be interested in selecting a ready-to-use swiftness reducer. For those of you who want to design your unique special gear educate or quickness reducer we offer a broad range of precision gears, types, sizes and materials, available from stock.
Precision Planetary Gearheads