Precision Planetary Gearheads
The primary reason to use a gearhead is that it makes it possible to regulate a huge 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 so current, would need to be as many times higher as the reduction ratio which can be used. Moog offers an array of windings in each body size that, coupled with an array of reduction ratios, provides an range of solution to productivity requirements. Each combination of electric motor and gearhead offers exceptional advantages.
Precision Planetary Gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Accuracy 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 drive will gratify your most demanding automation applications. The compact style, universal housing with precision bearings and accuracy planetary gearing provides great torque density and will be offering high positioning performance. Series P offers actual ratios from 3:1 through 40:1 with the best efficiency and cheapest backlash in the market.
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: Fits any servo motor
Output Options: End result with or without keyway
Due to the load sharing characteristics of multiple tooth contacts,planetary gearboxes supply the highest torque and stiffness for any given envelope
Balanced planetary kinematics by high speeds combined with associated load sharing produce planetary-type gearheads ideal for servo applications
True helical technology provides improved tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces easy and quiet operation
One piece planet carrier and result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Improves torsional rigidity
Efficient lubrication forever
The huge precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and offer high torque, excessive radial loads, low backlash, high input speeds and a little package size. Custom variations are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest performance to meet your applications torque, inertia, speed and precision requirements. Helical gears present smooth and quiet procedure and create higher electrical power density while maintaining a small envelope size. Available in multiple frame sizes and ratios to meet up various application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and precision planetary gearbox beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide even more torque ability, lower backlash, and tranquil operation
• Ring gear lower into housing provides greater torsional stiffness
• Widely spaced angular contact bearings provide output shaft with huge radial and axial load capability
• Plasma nitride heat treatment for gears for excellent surface have on 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
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 SPEED (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
Consistent misconceptions regarding planetary gears systems involve backlash: Planetary systems are being used for servo gearheads because of their inherent low backlash; low backlash can be the main characteristic requirement of a servo gearboxes; backlash is a way of measuring the precision of the planetary gearbox.
The truth is, fixed-axis, standard, “spur” gear arrangement systems could be designed and developed just as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement for servo-structured automation applications. A moderately low backlash is recommended (in applications with high start/stop, forward/reverse cycles) in order to avoid interior shock loads in the apparatus mesh. Having said that, with today’s high-image resolution motor-feedback products and associated action controllers it is simple to compensate for backlash anytime you will find a change in the rotation or torque-load direction.
If, for as soon as, we discount backlash, after that what are the causes for selecting a more expensive, seemingly more technical planetary devices for servo gearheads? What positive aspects do planetary gears give?
High Torque Density: Compact Design
An important requirement for automation applications is substantial torque ability in a compact and light package. This high torque density requirement (a high torque/quantity or torque/weight ratio) is important for automation applications with changing substantial 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 means a planetary equipment with claim three planets can transfer three times the torque of a similar sized fixed axis “normal” spur gear system
Large rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading circumstances. The load distribution unto multiple gear mesh points means that the load is reinforced by N contacts (where N = quantity of planet gears) consequently raising the torsional stiffness of the gearbox by aspect N. This means it substantially lowers the lost motion compared to a similar size standard gearbox; which is what is desired.
Added inertia results in an extra torque/energy requirement of both acceleration and deceleration. Small gears in planetary system lead to lower inertia. In comparison to a same torque score standard gearbox, this is a good approximation to say that the planetary gearbox inertia can be smaller by the sq . of the amount of planets. Once again, this advantage is definitely rooted in the distribution or “branching” of the load into multiple equipment mesh locations.
Modern day servomotors run at excessive rpm’s, hence a servo gearbox should be able to operate in a reliable manner at high source speeds. For servomotors, 3,000 rpm is pretty much the standard, and actually speeds are frequently increasing as a way to optimize, increasingly sophisticated application requirements. Servomotors operating at speeds in excess of 10,000 rpm aren’t unusual. From a rating perspective, with increased rate the energy density of the electric motor increases proportionally without the real size enhance of the motor or electronic drive. Therefore, the amp rating stays a comparable while just the voltage should be increased. An important factor is with regards to the lubrication at great 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 unique means such as costly pressurized forced lubrication devices can solve this issue. Grease lubrication is usually impractical as a result of its “tunneling effect,” in which the grease, as time passes, is pushed away and cannot movement back into the mesh.
In planetary systems the lubricant cannot escape. It really is consistently redistributed, “pushed and pulled” or “mixed” in to the gear contacts, ensuring secure lubrication practically in any mounting posture and at any speed. Furthermore, planetary gearboxes can be grease lubricated. This feature is usually inherent in planetary gearing due to the relative action between the different gears making up the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For much easier computation, it is preferred that the planetary gearbox ratio is an actual integer (3, 4, 6…). Since we are very much accustomed to the decimal system, we tend to use 10:1 even though it has no practical advantages for the pc/servo/motion controller. Basically, as we will have, 10:1 or more ratios will be the weakest, using minimal “balanced” size gears, and therefore 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 found in servo applications happen to be of this simple planetary design. Shape 2a illustrates a cross-section of this kind of a planetary gear arrangement using its central sun equipment, multiple planets (3), and the ring gear. The definition of the ratio of a planetary gearbox displayed in the shape 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 need to have the same diameter as the ring equipment. Figure 2b shows sunlight gear size for different ratios. With an increase of ratio sunlight gear size (size) is decreasing.
Since gear size affects loadability, the ratio is a strong and direct impact to the torque rating. Figure 3a shows the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, the sun gear is huge and the planets happen to be small. The planets have become “slim walled”, limiting the space for the earth bearings and carrier pins, hence limiting the loadability. The 4:1 ratio can be a well-balanced ratio, with sunlight and planets having the same size. 5:1 and 6:1 ratios still yield pretty good balanced equipment sizes between planets and sunshine. With larger ratios approaching 10:1, the small sun gear becomes a strong limiting factor for the transferable torque. Simple planetary designs with 10:1 ratios have really small sunshine gears, which sharply restrictions torque rating.
How Positioning Precision and Repeatability is Suffering from 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 has practically nothing to perform with the quality or precision of a gear. Only 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 query is, “What gear homes are influencing the accuracy of the motion?”
Positioning accuracy is a way of measuring how actual a desired position is reached. In a shut loop system the prime determining/influencing elements of the positioning reliability are the accuracy and resolution of the feedback device and where the position is definitely measured. If the position is certainly measured at the final outcome of the actuator, the affect of the mechanical elements could be practically eliminated. (Immediate position measurement is utilized mainly in high accuracy applications such as for example machine tools). In applications with less positioning accuracy necessity, the feedback transmission is generated by a opinions devise (resolver, encoder) in the electric motor. In cases like this auxiliary mechanical components mounted on the motor such as a gearbox, couplings, pulleys, belts, etc. will impact the positioning accuracy.
We manufacture and design high-quality gears along with complete speed-reduction systems. For build-to-print custom parts, assemblies, design, engineering and manufacturing solutions speak to our engineering group.
Speed reducers and gear trains can be classified according to gear type along with relative position of suggestions and result shafts. SDP/SI offers a multitude of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual productivity right angle planetary gearheads
We realize you may well not be interested in selecting a ready-to-use velocity reducer. For anybody who wish to design your very own special gear educate or swiftness reducer we offer a broad range of precision gears, types, sizes and material, available from stock.
Precision Planetary Gearheads